This study will evaluate the effects of chronic nonpulsatile blood flow in an alive, awake animal for periods of up to three months. The technique utilizes two nonpulsatile blood pumps to replace the function of right and left ventricles and then fibrillating the animal's heart. Thus, there is no competition between the beating heart and the nonpulsatile pumps. This technique has been successful in one animal who has been maintained for a period of 34 days in the nonpulsatile state and showed no abnormality of organ function apart from the initial transient effects of anesthesia and surgery. This study will allow evaluation of the effects of chronic nonpulsatile blood flow uninfluenced by the effects of surgery or trauma, evaluation of whether the animal can adapt to the nonpulsatile blood flow and hence determine the necessity of pulsatile blood flow for the maintenance of mammalian physiology. Such information has important use in the artifical heart program.